A substrate guided relay may be utilized in a head-up display (HUD) system or the like to generate one or more copies of an input light and to homogenize the input light at the pupil of the user's eye. Such a substrate guided relay generally may comprise an input coupler, a slab guide, and an output coupler. For a uniformly illuminated pupil, it may be beneficial to have additional copies of the input light and to provide additional homogenization of the output light. If an additional element such as a homogenizer is added to the substrate guided relay to increase the uniformity of the light output, very tight tolerances may be involved in aligning the additional element with the other elements of the substrate guided relay, and reflections from the surfaces of the additional element need to be accounted for, making fabrication of a such a device more difficult.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.